A gene named Wide Awake by researchers increases the brain's response to the inhibitory neurotransmitter GABA and allows fruit flies to sleep and wake at appropriate times. Wide Awake gene activity increases near dusk in a normally functioning fruit fly.
Neurons in the brain function as a clock for a fruit fly, allowing it to sleep in the evening and stay awake during the day. The Wide Awake gene helps the neurons function by controlling how sensitive they are to the neurotransmitter GABA. A neurotransmitter is a chemical that functions in signalling between neurons. GABA is an inhibitory neurotransmitter, meaning that it prevents activity in the neurons with which it interacts.
Some fruit flies have a mutation of their Wide Awake gene. The mutant gene does not cause enough GABA sensitivity in the brain meaning that the mutant flies remain aroused and excited at night and have difficulty sleeping, much like a human with insomnia. In fact, the Wide Awake gene exists in other types of animals, including mice, chickens and humans.
Researchers hope that experiments with sleep regulation in fruit flies lead to a better understanding of sleep patterns and regulation in humans. Understanding the genetic and chemical pathways that cause sleep may help scientists treat people suffering from insomnia.